Electrical machining techniques, when applied to the forming of a 3D contour or surface pattern in a workpiece, commonly require a tool electrode three dimensionally shaped to conform to the desired contour or surface pattern. Furthermore, a multiplicity of such electrodes of identical or similar configuration and size must be prepared in order to compensate for the wear which the electrodes or tools suffer during the erosion process or in the interest of minimizing the machining time to achieve the end of a desired machined precision and surface finish. Preparation of such precision formed and multiple electrodes is obviously time consuming and laborious.